Electrical switches are often used in applications where it is necessary to install and replace the switch in an electrical circuit without disassembling the switch or circuit, and these tasks may be performed under extreme time constraints. It has therefore been suggested to dispose an electrical switch in a housing having electrical contact pins connected to the switch and extended from the housing to form a modular switch assembly that may be readily connected to an electrical pin connector of an electrical circuit. Electrical switch assemblies connected or plugged into a contact pin connector are generally mounted in a panel, and the electrical connection is made by frictional contact between the electrical contact pins and the electrical contact pin connector, which may separate when subject to operational and environmental conditions.
Many electrical switch assemblies are used in applications where the status of the switch itself, or a function controlled by the switch, is not readily apparent to a switch operator, as may be the case in switch assemblies used, for example, in submersible and aerospace technologies. To overcome these problems, it has been suggested to include an electrical or mechanical display on the switch or switch assembly to indicate switch status, that is, to indicate whether the switch is opened or closed, or to indicate status of a remote activity.
Electrical switch assemblies are also used in environments subject to varying and extreme ambient lighting conditions, as may be the case in an aircraft cockpit instrument panel, where brilliant sunlight may be transmitted through the cockpit windows. These conditions may inhibit the pilot or switch operator's ability to ascertain the status of the switch by obscuring visibility of the switch or the switch status display indicator. In the past, some switch assemblies have employed bright incandescent light bulb illuminated displays to indicate switch status under extreme ambient lighting conditions. Incandescent light bulbs however require substantial power to operate, and generate a substantial amount of heat that must be dissipated by the switch assembly or by the panel in which the switch assembly is mounted. Additionally, many applications have a limited capacity to provide power for switch status display indicator purposes, and a limited capacity to dissipate heat. For example, in aircraft instrument panels, switch assemblies are often disposed adjacent other heat sensitive instruments that may be adversely affected by heat generated by a switch assembly. Further, some illuminated displays form a part of the switch actuator which may become very hot and uncomfortable for a switch operator to touch. This is particularly true of momentary type switch assemblies in which the switch operator is required to depress and maintain pressure on a switch actuator to operate the switch. Additionally, despite the use of brightly illuminated switch status display indicators, there may still be situations where the switch operator is unable to ascertain the switch status by relying on a mere visual observation of the switch or the switch status display indicator. There is therefore a need for an advancement in the art of electrical switch assemblies with switch status indicators.
It is an object of the present invention to provide a novel electrical switch assembly.
It is also an object of the present invention to provide a novel electrical switch assembly that may be removably installed or connected to an electric circuit without special expertise.
It is another object of the present invention to provide a novel electrical switch assembly that may be connected to a contact pin connector and lockably secured thereto.
It is another object of the present invention to provide a novel electrical switch assembly with a low power, illuminatable switch status display indicator that is visible under extreme ambient lighting conditions.
It is a further object of the present invention to provide a novel electrical switch assembly that efficiently dissipates heat generated by an illuminatable switch status display indicator.
It is still a further object of the present invention to provide a novel electrical switch assembly with audible and tactile switch status indicators perceptible to a switch operator.
Accordingly, the present invention is directed toward a method and apparatus for an electrical switch assembly generally comprising a snap-action electrical switch disposed in a module frame assembly and connected to electrical contact pins for mating with a contact pin, or socket, connector. A switch module assembly having a ribbed collar is pivotally connected to the module frame assembly and includes a switch actuator assembly disposed on a shaft movable in and out of the module frame assembly for actuating the snap-action electrical switch. The switch actuator assembly includes a latch spring guide interactable with a latch spring hook disposed in the module frame assembly to control the actuation Of the snap-action electrical switch. The latch spring guide may be configured for either "alternate" or "momentary" actuation of the snap-action electrical switch and emits audible and tactile switch status indicators perceptible to an operator. The module frame assembly and switch module assembly are releasably connectable to and form an integral unit with a cap base assembly having a cap module with a low power LED illuminated display indicator visible under extreme ambient lighting conditions. The integral unit is receivable in a switch connector module, or housing, that may include an electrical contact pin socket and is mountable in a bracket. The ribbed collar of the switch module assembly is extendable into and engagable with corresponding slots in sidewalls of the switch connector module to lock the integral unit therein upon pivoting the ribbed collar relative to the module frame assembly.
These and other objects, features and advantages of the present invention will become apparent upon consideration of the following Detailed Description of the Invention with the accompanying drawings.